Although research with animal models figures prominently in the study of other major public health threats, little or no research with animal models of child abuse and neglect is currently being conducted. The spontaneous occurrence of maternal abuse of offspring in group-living monkeys is a phenomenon that shares several similarities with human child abuse and neglect. The determinants and consequences of this phenomenon, however, have not been systematically investigated. This project investigates the causes of the spontaneous occurrence of infant abuse in a large population of group-living rhesus macaques. The project will be conducted in 5 years at the Field Station of the Yerkes Regional Primate Research Center. The specific aims of this project are: to investigate the incidence of infant abuse within and across families over a period of 35 years, using a database already available; to gather a large set of data on the parenting style of abusive mothers, the behavior of abused infants, and the circumstances in which abuse occurs; to investigate the role of estrogen and the opioid and serotonergic systems in the etiology of maternal abusive behavior with physiological measurements and pharmacological challenges; to investigate the mechanisms underlying the intergenerational transmission of infant abuse by cross-fostering female infants between abusive and nonabusive mothers and then studying their maternal behavior and its physiological correlates when they give birth to their own infants. At the end of the proposed project, a large body of genealogical, demographic, behavioral, physiological, and pharmacological data concerning infant abuse will be available. This information will be used to develop biological, social, and behavioral predictors of infant abuse and to identify at-risk individuals and situations. This project will significantly enhance our understanding of the causes and consequences of infant abuse in primates and could have important implications for prevention and treatment of child maltreatment as well.